<<I think you should figure on being at a lower tax rate after retirement. I would use 15% instead of 28%.>>

That's a generality that will get too many folks into trouble. Surprisingly, many folks will stay in the same tax bracket they are in right now (i.e., 28% where most taxpayers are today). It's true many will also drop to the 15% bracket. For them, the traditional IRA will be better. However, I disagree strongly that everyone should plan on being in the 15% bracket, particularly those who did more than rely on Social Security to provide a third or more of their income in retirement. For those, your advice is a disservice. They, in particular, will remain in at least the 28% marginal tax bracket. And for them, the Roth will win out over the traditional IRA.